Cosmic Geoff

Some quick results on Mars from the morning of 20 July. The seeing was good and Mars at a good altitude.  Equipment: CPC800, ASI224MC with IR-cut and IR-pass filters, ADC.

The surface features show more clearly in infrared.  I forgot to try a Barlow lens on this small target, but have not had any good results with the cheap Skywatcher x2 Barlow in the past.  So these images are kinda small; I was going to x2 them in Photoshop but am having a problem with my network just now.  

The surface detail checks out as Syrtis Major and Hellas with the southern icecap.

To be frank, I would not buy either.  Both are mounted on lightweight mounts and I would prefer something more substantial. I have the SLT mount and thought it on the wobbly side with a 127mm Mak, so got a more robust equatorial mount and then built a wood tripod for the SLT mount head.  I have stuck with handsets rather than have the complication of wifi.  With the wifi model, you are in effect providing a wifi connected handset instead of the manufacturer.   I once worked in a lab where wifi would not work on our laptops because of the electrrical interference.

There has been discussion about those OTAs and their weight, but they are probably identical.  The same OTA can be had with various other mounts of a more substantial nature, at more substantial prices, or as just the OTA.  You may have noticed that one of the budget outfits costs the same as the OTA (= a free wobbly mount).

You will probably have to upgrade the 9/10mm eyepiece regardless. Kit eyepieces are notoriously poor - they are included to get you started but the manufacturer wants to keep the kit price down.

1 hour ago, DanielC said:

Is a light pollution filter a good investment or is it a waste for money? I live in a suburban area, and I won't be doing astrophotography.

EDIT:  I just thought of another question. Do you collimate SCTs? Or is that something you only have to do for Newtonians?

Light pollution filter: I don't use one.  The old street lights could be filtered out but the new LEDs emit a continuous spectrum and are far more difficult to filter out. There are filters that are claimed to work, but they are expensive and of limited effect.

SCTs can be collimated, but are much less prone to going out of collimation than Newtonians.  You may never have to touch this adjustment.  My used C8 was horribly out of adjustment when I bought it, but I collimated it on a bright star and have never had to touch it since.

5 minutes ago, DanielC said:

To deal with the dew and cooling time, I will keep the telescope in my garage, or I'll make sure to bring it outside early.

I never found the cooling time a serious problem with my C8 SE.  One can view less demanding targets first.

  A dew shield is an essential accessory.  If you don't want to buy a smart-looking plastic one, you could make your own shield.

The various Maksutovs, sold under various brands, seem to mostly originate from the same Chinese factory.  The one you link looks the same as mine except for the colour. One sees very few complaints about any of them and the design is robust and unlikely to ever need any adjustment. So buy with confidence.

You should be able to see bands on Jupiter easily with a 127mm Mak.  If you search through the Planetary Imaging section of this forum you should find some images showing what 127mm Mak optics can do - but caution, a visual observer will be unlikely to see as much.

I recently used my 127mm Mak to view Venus in the daytime, using the Sun as a Goto reference (extreme caution required.) I use my 102mm f5 Startravel refractor for EEVA imaging, and a couple of nights ago put it in the only position in the backyard from which I could view Comet Neowise.  The smaller scopes are far handier for brief grab'n go exercises (a 127 may not seem much smaller than a 150mm, but it's about half the bulk.)

By the way, the Mak you link is outfitted for daytime use. For astronomy you'd want a 90 deg star diagonal (mirror or prism) not the  45 deg correct-image prism.

GoTo or not GoTo is a perennial question on which no three backyard astronomers will agree. It is particularly useful in urban skies, or if you want to look at objects rather than look for them.  On the other hand, some people just don't get on with GoTo or are confused by the setup procedures and prefer the traditional simpler mounts.

Since you have expressed a preference for GoTo, you should go for it. 🙂

For your initially quoted budget you would have more choice of outfit if you go for a smaller aperture, i.e. 127 or 130mm, which is still enough to give you many nights of enjoyment, particularly if you can actually find the objects with a GoTo.  A 127mm Maksutov, unlike some of the entry level reflectors, will be a good quality instrument optically and mechanically.  It is the kind of instrument you will keep even if you graduate to something bigger.

The lower cost mounts tend, alas, to be on the wobbly side.  If you want a decent aperture telescope on a really solid mount, the total cost rockets to a wallet-emptying degree.

Three element eyepieces should be avoided.  Plossl eyepieces are adequate in many situations, particularly for longer focal ratio telescopes, while f5 Newtonians will probably benefit from a more exotic eyepiece design.  I am not an eyepiece expert though

9 hours ago, murph_man99 said:

just checked and the AWB OneSky Reflector Telescope is out of stock till August.  Should I buy the Skywatcher 130 Heritage?

Obviously yes, unless you live outside the UK and can't find a supplier/importer. Buy from an astro specialist, not Amazon.

That's an impressive improvement from the original bouncy video. The results are markedly better in IR.

12 hours ago, astroman001 said:

Correct this either with the yellow/blue slider in colour balance or by boosting blue channel in levels until the zones look whitish.

Interesting point. I'll try correcting the colour at the next opportunity.

If you are having trouble aligning the C8 SE, a Starsense is not necessarily going to help.  You need to find out why you are having trouble, and sort it.   The Nexstar system on an Alt-Az mount is  almost as simple as it gets. You should try aligning an equatorial Sywatcher Synscan...  😦

Basically, to align the C8 SE, get the tripod level - placing the bubble level supplied temporarily on the top plate (on my second hand kit it came attached to the lower mount with a bit of sticky but should be used on the top plate)

Make sure the time, date, location are entered in the right format and match your location and time zone and daylight saving. Causes endless fun for unwary newbies.

Then do a two star auto align (or one star align, or Solar System align - your choice.)  Just Read The Manual.

As for the Starsense, once set up, it works well and is a good complement to the C8 SE in a quick deploy carry out setup.  I have found that with the Starsense attached it is not necessary to level the tripod providing you are using it on a hard surface e.g. patio or backyard concrete.  The initial setup is not straightforward though, and the manual is about as easy to follow as  BSc physics course. The manual contains at least one critical error:

Starsense Manual - First Time Setup - Calibrate Centre,

paragraph 2.  ...in that region of sky.

Press ALIGN. Centre the star. (coarse align) (fine align) as 3. below (handwritten addition)

3. Attach your widest angle/lowest power eyepiece...

As for eyepieces, you really need to add to the 25mm that came with it.  You will get 57 kinds of advice about this, but I suggest a 15mm Celestron Omni Plossl and a 8mm or 10mm of whatever eyepiece model takes your fancy.  And maybe a cheap 8-24 mm zoom.  And leave the Barlow in its box; you don't need it with a f10 SCT, except for planetary imaging.

I can't comment on the "Bresser full HD deep-sky camera" as this seems to be a generic trade name. 

I hope all this helps.

+12 volts is one of the nominal output voltages from a PC PSU - the exact level when measured by a digital multimeter may well be somewhat higher or lower - real example from working PC: 11.96v (varying slightly).  Sample output ratings: +5v = 30 amps, +12v = 15 amps.

Plossls should be good enough for a f11 telescope, particularly for the longer focal length eyepieces.

An image of Jupiter with a transit of Io, showing the moon and its shadow, plus another moon (Callisto).  This was the best of a number of images.  I used shorter runs of 3000 images while contending with thin moving cloud, then 5000 when the cloud moved away. But the seeing seemed to deteriorate, so this is the best image.  I left the gear out in hopes of imaging Mars later but by 3am on the 18th, the sky had totally clouded over.

Equipment: CPC800, ASI224MC, ADC, processed in Registax6. Best 20% of 3000 frames.

The "Wavelet" section of Registax has six sliders. I have been in the habit of using just the top one, but adding some action with the second one definitely improved last night's set of images.

I would try using a desktop computer power supply.  These are mains powered, switchmode,  and have outputs of +5v, +12v and usually other voltages like -12v. The +5v and +12v outputs will deliver several amps, depending on the supply rating.  The +5v is the regulated output so you should ensure this is sufficiently loaded.  All 0 volt returns are connected. The only bit you will have to make yourself is the 7.4 volt regulator circuit, powered from +12v.  And remember you will need to feed a signal into one of the connectors to make a computer PSU turn on.

You could blank out the chipped part of the objective with black tape etc. That should improve the contrast. I did this with a vintage Ross 40mm scope that arrived with a spall at the edge of the objective. The aluminium lens cell and glare shield parts would not undo - somebody already tried.

This would be a good outfit for having a go at planetary imaging - preferably with a dedicated planetary video camera and processing the results with stacking software.

OTOH, for deep space astrophotography the scope and particularly the mount are not well suited for this, and beyond having a dabble to see what you can achieve, you should think of buying something else.  The book "Making Every Photon Count" (available from forum sponsor FLO) is recommended as the standard reference.

If you look in the imaging sections of this forum, you will see what kit is being used.

I have used a C8 for various things, ditto several Celestron Nexstar mounts.

I suspect that your photometry isn't the most demanding application re the mount so I can't see why it should not work.

I should point out though that the C11 is a big OTA and though not extremely heavy, mounting it by yourself might not be any fun. 

If you don't need an equatorial and field rotation is not an issue you could use an alt-azimuth mount.  Not that there are many options. But there is a CPC1100 which if it is anything like the CPC800 will have a very stable and well behaved mount.  But the OTA/mount assembly is very heavy and I would not like to try lifting one.  If you are having a permanent observatory these weight & handling problems would be solved.

  Ideally you want a dedicated  planetary video camera. It seems you refer to an infrared filter.  My ZWO camera, having some IR response, can be fitted with an IR-cut filter for normal use or an IR-pass filter for imaging in infrared.   Video exposure times are about 10x longer in infrared.

If your camera is unmodified (red filter not removed) ir may have no IR response at all.

There is a website where you can order rubber lens caps. I used it to order a replacement objective cap the right size for my binoculars.

Is it an astro scope (inverted view) or non-inverted view (terrestial)?  My Ross is terrestrial, with an erecting set that clearly increases the effective focal length so that the magnification with a 20mm Plossl eyepiece is crazily high.

Yours looks like an interesting purchase.

With a smaller ROI (region of interest), e.g. 320x240 pixels, the planet image is more closely cropped and the frame rate is higher, which means the imaging total time for a large number of video frames is less, which may improve the quality of the final result.   A smaller ROI puts greater demands on your guiding, however.   With a faster frame rate there is less time for the planet to drift out of frame if the tracking is less than perfect. 

4 hours ago, StarGazingSiouxsie said:

The ADC sounds intresting. Are they straightforward to install? I was observing Jupiter & Saturn (or trying to ) with Cassie a few nights back. They were both at appx 20 degrees up at the time. I was not able to get focus very well, although I was using low end eyepieces. Maybe turbulence in the atmosphere affected my efforts? I was very disappointed. So maybe the ADC will help when observing at those altitudes.

The ADC is very straightforward to install. Just fit it between diagonal and eyepiece and then do a major re-focus. If you noted any blue or red fringing, the ADC, correctly set, will get rid of it.

Is sounds like turbulence was to blame for the "bad focus" - situation normal: blurry except for brief glimpses of a clearer view.  At 20 deg this is to be expected. I suspect you will find it looks the same with the $350 eyepieces.

You can use anything so long as it delivers +12v with sufficient current capacity for long enough.

I have a car starter with cigarette-lighter style outlet, a Celestron LiFePo power tank, and a 12v 7Ah sealed lead acid battery. They all do the job of powering a C8 SE. 

Anything that looks really small or really cheap may not have enough capacity for a long session.

The C8, (and presumably the C9.25) comes with a nice 1.25" prism diagonal. So far, I have seen no reason to change it for another diagonal which would most likely not give any visual improvement regardless of cost.  Same for 2" components. I have a 32mm Plossl which I rarely bother to get out of the box.  If I want widefield, I have other scopes.

Looks like a genuine old scope that has been fitted to a non-original mount.  It is unlikely to take modern eyepieces, though that might not be an issue if you have the originals. It could be worth something in three figures if in fair condition and tidied up. Do you feel lucky? 

I have a vintage Ross brass refractor which turned out to work superbly when kitted to go on a modern astro mount, and with the original 32mm diameter eyepiece temporarily replaced with a 31.7mm (1.25") dia eyepiece + a slip of card packing.  Totally blew away the 70/700 supermarket refractor I had a while ago.